DESCRIPTION: (Adapted from the Investigator's Abstract.) The primary goal of this proposal is to continue an already established research collaboration between Dr. William Barrow (PI), Southern Research Institute, and Dr. Nalin Rastogi (Co PI) of the Institut Pasteur. The collaboration began when Dr. Barrow served a sabbatical leave in Dr. Rastogi's laboratory as a part of a Fogarty Senior International Fellowship from 1992, 1994. The purpose of that fellowship was to develop a better understanding of the Mycobacterium avium complex with regard to pathogenicity, virulence and multiple drug resistance. Those studies were designed as interactive with two NIH grants that were a part of the PI's research program, and as a result were important in the continued funding of those grants. In addition, several manuscripts were published as a result of those research efforts. Dr. Rastogi has been with the Institut Pasteur in Paris for more than ten years. Last year he moved to the Institut Pasteur on the island of Guadeloupe, France, where he is currently the Chief of the Tuberculosis and Mycobacteria Unit. As a result of that move, the collaboration with Dr. Rastogi offers a unique situation for extended studies involving AIDS related pathogens such as M. avium and M. tuberculosis. This is particularly important when one considers the impact of multiple drug resistant (MDR) strains of M. tuberculosis and the importance of early detection and monitoring of these strains once they develop. Another group of mycobacteria that poses a threat to HIV+ individuals is the M. avium complex, which is not only resistant to multiple drugs, but which is not well understood with regard to its pathogenicity. As the numbers of HIV+ individuals increases worldwide, it is particularly important to develop a global surveillance system for the isolation and containment of MDR strains of M. tuberculosis, and to evaluate new methods for treatment of MDR strains of not only M. tuberculosis but those of the M. avium complex as well. The specific aims of this proposal will be to 1) isolate and characterize strains of M. avium and M. tuberculosis form HIV positive and HIV negative patients in Guadeloupe and the surrounding Caribbean area, 2) obtain drug susceptibility patterns for each strain, and 3) characterize strains of M. avium and M. tuberculosis by restriction fragment length polymorphism for further studies on pathogenicity and drug resistance. This collaboration will not only allow the PI to enhance his current NIH funded research efforts with M. avium but also allow him to expand his research efforts to another important AID related pathogen, M. tuberculosis.